<!--
 * @Descripttion: 
 * @version: 
 * @Author: wtzhang
 * @Date: 2021-09-23 09:31:13
 * @LastEditors: wtzhang
 * @LastEditTime: 2021-09-23 09:39:06
-->
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<style>
  div {
    height: 100px;
  }
  .parent {
    /* 表格的单元格的宽度会自动分配 */
    display: table;
    table-layout: fixed;
    width: 100%;
  }
  .left, .right {
    display: table-cell;
  }
  .left {
    width: 100px;
    background-color: blueviolet;
  }
  .right {
    background-color: coral;
  }
</style>
<body>
  <div class="parent">
    <div class="left"></div>
    <div class="right"></div>
  </div>
</body>
</html>